Shumann's Piano concerto thakes less than 30 minutes and it is really fun to play.
Greig's Piano concerto can be played in about 30 minutes.
Handel has some really nice piano concertos and they arent overplayed.
Rachmaninoffs 1st piano concerto is again under 30 minutes
Both af Mendelssohns are good choices, but I prefer the 2nd
Ravels piano concetos are also good.
From liszt you could play the Malediction
If you are really ambitious you could try Chopins Polonaise Brilliante. But It is heard so often that it is really easy to find mistakes in it. But it is still a brilliant piece
You could try Rachmaninoffs Rhapsody on a theme of Paganini.
Since I am Armenian i must also put in Khachaturian piano concerto, And the very difficult Heroic Ballade By Arno Babadjanian.
I am sure there are many other good pieces but that is all i can think of for now.

Good luck. Ara